Background: Actinic dermatitis is an environmental skin disease resulting from excessive exposure to ultraviolet light irradiated by the sun. This phototoxic reaction affects dogs and cats, particularly with short hair and lightly pigmented skin, exposed to sun light. Primary lesions are typical from a sunburn and chronic exposure, and may induce to a premalignant lesion known as actinic keratosis, which may develop to neoplasms. The aim of the present study was to describe a retrospective study of actinic dermatitis and the occurrence of cutaneous neoplasia in dogs presented to a Veterinary Medical Teaching Hospital (HCV/UFRGS) in Porto Alegre, Rio Grande do Sul, Brazil in a period of 10 years.Materials, Methods & Results: A retrospective review of medical records from January 2009 to December 2019 was performed to identify dogs with actinic dermatitis. Twenty-eight dogs were diagnosed based on a history of sun exposure and skin lesions including erythema, scaling, comedones, thickened skin, hyperpigmentation, ulceration and/or secondary infections on poorly pigmented skin. In addition, in twelve dogs (42.8%) the disease was also confirmed by histopathology. Cutaneous lesions locations were previously defined as head, limbs, neck and trunk. The head was subdivided in chin, ears, face, lips and nasal plane; the limbs in pelvic and thoracic; and the trunk, in abdomen, dorsal pelvis, perianal and thorax.  All 28 dogs diagnosed with actinic dermatitis in the study had been chronically exposed to solar radiation and had light skin and coat. Dogs were between 3 and 20 years old, mean 7.6 years and median 7 years, mostly female dogs (64.2%) and neutered or spayed (64.2%). The most affected breeds were American Pitbull Terrier (35.7%) and Boxers (28.5%). Other breeds were Bull Terrier, Dalmatian, Dogo Argentino and Scottish Terrier. In 15 cases, tumors were confirmed by cytopathology or histopathology, resulting in 9 different skin tumors and two types of cysts (epidermoid and follicular). Among these, the most prevalent malignant neoplasm was squamous cell carcinoma (66.7%), followed by mast cell tumor (40%), hemangiosarcoma (26.6%), and basal cell carcinoma (6.6%). Five benign tumors were identified: hemangioma (13.3%), fibroma (6.6%), lipoma (6.6%), sebaceous adenoma (6.6%) and trichoepithelioma (6.6%). The most prevalent location for actinic lesions was the trunk (92.8%), being more prevalent on the ventral abdomen (82.1%). Actinic lesions were also present on head, neck and limbs. In 13/15 patients (86.6%), actinic lesions and at least one neoplasia location matched.Discussion: Actinic dermatitis tends to occurs in mid-aged to senile dogs because of the disease progressive and chronic behavior and owners delay to detect early clinical signs. In fact, actinic dermatitis was diagnosed at the average age of 7.6 years in the present study. The skin lesions were mostly located on light hair areas and were not observed on pigmented skin. The trunk (mainly the abdomen) had higher frequency of skin lesions compared to other anatomic areas, possibly because some dogs like to sunbathe at dorsal or lateral recumbency, some floor types can reflect sunlight, and some ventral abdomen are hairless. Ultraviolet radiation causes important local and systemic immunogenic changes. The impairment of the immune system and antigen recognition can influence cutaneous susceptibility to develop neoplasm. In conclusion, approximately 50% of the dogs with actinic dermatitis were associated with different skin neoplasm. The most prevalent was squamous cell carcinoma, mast cell tumor and hemangiosarcoma. Actinic lesions and neoplasm matched location in almost all patients with both conditions, however it was not possible to define if solar radiation had predisposed the occurrence of all observed neoplasms. Further studies are needed to prove the influence of ultraviolet radiation in the development of different cutaneous neoplasms.

Background: Sporotrichosis is a deep cutaneous mycosis caused by the Sporothrix species complex, dimorphic fungi of which at least five are of clinical importance: S. brasiliensis, S. globosa, S. luriei, S. mexicana, and S. schenckii sensu stricto. The disease affects humans and animals, especially cats, which can manifest a wide spectrum of clinical sings, from cutaneous-lymphatic involvement to disseminated form. Infection usually results from direct inoculation of the fungus into skin. Zoonotic transmission is associated with scratching or biting of sick cats. The aim of this work was to report an atypical case of bone sporotrichosis in a cat.Case: A 5-year-old, male, neutered, mongrel and indoor cat was present at the Veterinary Clinic Hospital, Federal University of Rio Grande do Sul (HCV-UFRGS), Porto Alegre, Brazil, with lameness and increased volume in the left hindlimb. The animal had been treated intermittently with itraconazole during the last three years due to another cutaneous lesion which was recurrent and undiagnosed. A firm and painful mass was found in tarsal region of left hindlimb, that had approximately 5 cm in diameter. Radiographic examination of the left tibial-tarsal joint revealed bone lysis in the fifth metatarsal calcaneus, in addition to periosteum proliferation in calcaneus, tibio-tarsal subluxation, presence of osteophytes in tarsal bones and increase in soft tissue volume. Histopathological analysis of the biopsied tissue showed piogranulomatous inflammation. No yeast-like structures were observed in cytopathological exam. Tissue fragments were plated and Sporothrix sp. complex growth in mycological culture (Sabouraud Cycloheximide Chloramphenicol Agar). Physiological tests (growth rate at different temperatures and assimilation of sucrose and raffinose) were conducted for the differentiation of the species of complex. Molecular identification was performed using panfungal primers (ITS3-F / ITS4-R). The diagnosis of bone sporotrichosis caused by Sporothrix brasiliensis was based on clinical signs, mycological (confirmed by isolation and identification in culture medium) and molecular methods. Treatment was based on excision of the limb associated with oral administration of itraconazole and silymarin for two months. Unfortunately, three months later new nodules were seen at the abdomen and biopsy samples were positive in a new fungal culture for Sporothrix sp. Oral treatment was then restarted for four months. The cat is now free of lesions for six months and clinical monitoring visit is usually done once per month.Discussion: Sporotrichosis is a fungal infection with worldwide distribution, mostly in tropical and subtropical countries, characterized by cutaneous and subcutaneous lesions with regional lymphocutaneous dissemination, but some pulmonary and systemic infections in human have been reported. Cats are frequently infected with sporotrichosis in Brazil and develop a scattered cutaneous condition. On the other hand, the systemic form of the disease have been more observed with a disseminated respiratory or systemic condition, including infection of the lungs, liver, spleen, kidney, testis, eyes, bones, central nervous system, gastrointestinal tract, and mammary glands may also be affected. The occurrence of bone sporotrichosis, without skin lesions, show the high susceptibility of these animals to infection by Sporothrix. Molecular methods for the differentiation of Sporothrix complex are needed when the conventional methodology (histopathology and culture) does not allow the identification of the agent. The reference standard for diagnosing sporotrichosis is microscopic characterization of the pathogen isolated in culture. In our study, although the culture was positive, PCR was necessary for detecting and identifying Sporothrix brasiliensis. The reported case of bone sporotrichosis emphasizes the importance of a conclusive and differential diagnosis in feline lytic bone lesions based on the detection of fungal in the tissue by molecular methods associated with the isolation of the agent in a fungal culture.

Background: Meningoencephalitis in cats is usually related to infectious diseases but may also be caused by the extension of bacterial infections originated in the middle or inner ear. This paper seeks to report on a case of encephalitis due to an infection in the middle/inner ear in a 15-year-old cat. The diagnosis was made through brain CT scan and culture and antibiogram of material collected during a ventral osteotomy of the tympanic bulla and reported grave intravascular haemolysis associated to the treatment with antimicrobial imipenem with cilastatin sodium that has already been described in humans but not in small animals in the researched literature.Case: A 15-year-old, male, castrated, Siamese cat was brought to the Veterinary Clinical Hospital of the UFRGS. The animal presented pyrexia and hyporexia, tested negative in the immunoenzymatic test to detect antigens of the FeLV and antibodies of the FIV. The animal had a history of three episodes of tonic convulsion within two days and otitis that hadgone untreated for 10 months prior to the consultation, with apparent spontaneous remission. After blood tests, serum biochemistry profile, abdominal ultrasound scan, chest x-rays and CT scan was requested. It revealed middle and inner otitis in the right ear. It was performed a ventral osteotomy of the right tympanic bulla. Material was collected for culture and antibiogram. It was confirmed that the animal had an inner otitis of bacterial origin by multi-resistant Klebsiella spp. that was sensitive only to antimicrobial imipenem with cilastatin sodium. Fifteen days into the treatment with this antibacterial combination, grave haemolysis was observed, probably associated to the use of the medicine. The patient died on the 17th day of the treatment which was not interrupted as per its owner’s decision. At necropsy, both in the tympanic bulla and liver were found mucous content and whitish lumps. The material collected from the tympanic bulla and cerebrospinal liquid were cultured post-mortem when the bacteria Klebsiella sp. was isolated in the CNS and no bacterial growth was observed in the right tympanic bulla.Discussion: This makes it possible to deduce that there was an intracranial expansion of the otitis which would explain the convulsions and, that due to the use of the antimicrobial agent, the growth of Klebsiella sp. in the tympanic bulla was inhibited. The final diagnosis was bacterial otitis with probable bacterial migration to the brain and liver. Suppurativemeningoencephalitis caused by the expansion of the inflammation deriving from middle/inner otitis has been reported as being the cause of convulsions in cats with bacterial isolation. The bacteria that was isolated from the tympanic bulla is in agreement with the microbiota present in middle/inner otitis in cats. Regarding haemolysis, there are no reports thatlink the use of carbapenems in small animals to it or that mention what the safe therapeutic dosage should be if they were administered. Regarding humans, there have been various reports of haemolytic anaemia caused by this type of medicine including carbapenems. It is also known that, in in vitro tests, imipenem may cause inhibition due to competition from human erythrocyte-glutathione reductase, in charge of defending the erythrocyte against haemolysis. It has been concludedthat meningoencephalitis caused by middle/inner otitis must be included as a differential diagnosis in case of convulsions in cats. Additionally, further studies must be carried out in order to determine both the efficacy and the toxicity of carbapenems in veterinary patients, including studies of the occurrence of grave haemolysis after they are administered.Keywords: meningoencephalitis, computed tomography, convulsions, imipinem, carbapenems.